As any 14-year-old will tell you, the true measure of a pop star’s popularity is how many friends he has on MySpace. And as far as friends goes, megastar rapper 50 Cent’s got plenty of ‘em — more than 908,000. But even 50 knows he’s going to have to harness more than just a well-organized MySpace contingent to top the 1.14 million copies he sold of his last album, “The Massacre,” in 2005.

That’s why he’s taking the interactive aspect of MySpace one step further by becoming a “Zwinky,” a fully-functioning avatar for Zwinky.com. The move coincides with the Sept. 4 release date for his next album, “Curtis,” on Interscope Records. Not only can fans add 50 as their “friend” on Zwinky, they can use his avatar as their own and customize it before hitting various social-networking sites — all the while spreading the word on the new album.

Chris “Broadway” Romero, 50’s manager, said the internet has always been a friend as much as it has been a foe in marketing his client’s music. After files of “The Massacre” leaked onto music-sharing sites before its scheduled release date, Interscope rushed out the album four days ahead of schedule. “It kinda threw things into a frenzy,” Mr. Romero said. “People had nowhere to go to find material, and we didn’t necessarily do any strategic partnerships with online sites. But music is about visibility now, and record companies are on their way to becoming advertising companies — looking forward to where the marketplace is going.”